1. Field of the Invention
The present invention relates to power management technologies for a graphics system, and more particularly, to a method and system for flexibly supplying power to a high-end graphics card.
2. Description of the Related Art
Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
With the increasing demand for realism and interactivity in graphics applications, high-end graphics processing units (GPUs) are required to handle more and more complex image processing tasks. These high-end GPUs include increasing number of circuit elements and thus consume significant amount of power. In a typical graphics card, the two primary power-consuming components are the GPU and the local memory unit. To ensure they operate properly, the graphics card includes some power supply circuits on the card to ensure theses components receive sufficient amount of power. With such power supply circuits placed alongside the GPU and the local memory unit on the same graphics card, the size of such a graphics card tends to be large. To make the matter worse, the power supply circuits are customized to support only a particular GPU type and/or a particular local memory unit type. So, if a different GPU type and/or a local memory unit type is needed, then the power supply circuits need to be redesigned, and the layout of the graphics card also needs to be altered. Moreover, having the power supply circuits, the GPU, and the local memory unit all on the same graphics card renders heat dissipation much more difficult to deal with.
To illustrate, FIG. 1 is a simplified block diagram of a conventional high-end graphics system 100. The graphics system 100 includes a GPU 102, a local memory unit 104, and other components such as digital to analog converter (DAC) and a phase lock loop device (PLL). The DAC and the PLL are collectively referred to as a conversion block 106, and a power supply unit 108. The power supply unit 108 is on the same circuit board with the GPU 102, the local memory unit 104, and the conversion block 106 of the graphics system 100. The graphics system 100 is typically placed into a Peripheral Component Interface Express (PCIe) slot of a computing device.
The power supply unit 108 is configured to supply voltages to the GPU 102, the local memory unit 104, and the conversion block 106 via NVVDD, FBVDD, and DACVDD and PLLVDD signals, respectively. The PCIe slot generally only supplies a power of 75 watts, which is insufficient for a high-end graphics card, such as the graphics system 100, that consumes anywhere from 200 to 300 watts. As the result, the power supply unit 108 needs additional wattage to drive the graphics system 100. A typical approach is for the graphics system 100 to receive power from an external power source (not shown in FIG. 1), such as the power supply of the computing device to which the graphics system 100 is attached to. Because the wattages from the external power source can be higher than what the system requires, dedicated power supply circuits are included in the power supply unit 108 to handle the needed conversion, which results in an increased in size for the power supply unit 108. As discussed above, if the graphics system 100 is redesigned to support a different GPU and a different local memory unit than the GPU 102 and the local memory unit 104, then the power supply unit 108 and the layout of the graphics system 100 also need to be redesigned. Having the power supply unit 108 along with the GPU 102, the local memory unit 104, and the conversion block 106 all on the same circuit board further worsens heat dissipation issues for the graphics system 100.
Thus, what is needed in the art is a method and system for flexibly supplying power to a high-end graphics card in a cost effective manner and addresses at least the problems set forth above.